Method for optical detection of bio-contaminants

• US 9,354,182 B2
• Filed: 02/26/2013
• Issued: 05/31/2016
• Est. Priority Date: 02/26/2013
• Status: Active Grant

• Current Assignee: National Optics Institute, Steris Inc (Steris Corporation)
• Original Assignee: National Optics Institute, Steris Inc (Steris Corporation)
• Inventors: Rochette, Daniel, Gallant, Pascal, Mermut, Ozge, Baribeau, Francois, Noiseux, Isabelle, Gosselin, Isabelle
• Primary Examiner(s): Xu, Robert
• Application Number:
  US13/777,053
• Publication Number:
  US 20140242717A1
• Time in Patent Office: 1,190 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61L 2/28 Devices for testing the effectiveness or completeness of sterilisation, e.g. indicators which change colour apparatus involving enzymes or microorganisms C12M1/34; methods involving enzymes or microorganisms C12Q1/00
• CPC Class Codes: A61L 2202/24 Medical instruments, e.g. endoscopes, catheters, sharps
• CPC Class Codes: G01N 2021/6417 Spectrofluorimetric devices
• CPC Class Codes: G01N 2021/6439 with indicators, stains, dyes, tags, labels, marks
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/6486 Measuring fluorescence of biological material, e.g. DNA, RNA, cells G01N21/6428 takes precedence
• CPC Class Codes: G01N 21/94 Investigating contamination, e.g. dust G01N21/85 takes precedence
• CPC Class Codes: G01N 2201/06113 Coherent sources; lasers
• CPC Class Codes: G01N 2201/068 Optics, miscellaneous
• CPC Class Codes: G01N 2201/0697 Pulsed lasers
• CPC Class Codes: G01N 2201/10 Scanning
• CPC Class Codes: G01N 2201/105 Purely optical scan

Abstract

A method and apparatus for optical detection of residual soil on articles (such as medical instruments and equipment), after completion of a washing or a rinsing operation by a washer. A soil detection system provides an indication of soil on the articles by detecting luminescent radiation emanating from the soil in the presence of ambient light.

Claims

1. A method for detecting presence of soil on an article, said method comprising:

introducing a luminescent agent to a detergent during a wash cycle of a washing apparatus, wherein the luminescent agent is a fluorescent agent that emits fluorescent light, said luminescent agent bound to soil present on the article;

rinsing the article to remove unbound luminescent agent;

exposing the article to laser light;

detecting light emanating from said article and generating light data corresponding thereto, said light emanating from said article including ambient light reflected by the article and light emitted by exciting the luminescent agent bound to the soil;

filtering the light emanating from said article at first and second predetermined frequencies; and

determining the presence of soil on the article based upon the filtered light received by a light detector, wherein said step of determining the presence of soil includes spectrally discriminating between the fluorescence light and the ambient light reflections based upon a measure of saturation of light intensities of combined fluorescence light and ambient light at the first frequency relative to light intensities of ambient light at the second frequency.

2. A method according to claim 1, wherein said fluorescent agent is bio-compatible.

3. A method according to claim 1, wherein said fluorescent agent is fluorescein.

4. A method according to claim 3, wherein said fluorescein concentration is in the range of about 0.001 mM to 90 mM.

5. A method according to claim 1, wherein said soil is an organic residue including one or more of the following:

blood, fat, mucous, lipids, carbohydrates, bone, hair, protein, and food product.

6. A method according to claim 1, wherein said luminescent agent can withstand temperatures exceeding 80°

C.

7. A method for detecting presence of soil on an article, said method comprising:

providing an article that has been washed and rinsed in a detergent having a luminescent agent that binds to soil residue present on the article;

exposing the article to excitation light having a first frequency, to emit fluorescent light of a second frequency from the luminescent agent bound to the soil residue;

filtering light through a beamsplitter having a dichroic element to reflect the excitation light of the first frequency and to allow the fluorescent light of the second frequency;

detecting the fluorescent light emanating from the luminescent agent as indicative of the soil residue present on the article; and

determining the presence of soil residue on the article based upon the detected light, wherein said step of determining the presence of soil residue includes spectrally discriminating between the fluorescence light and the ambient light reflections based upon a measure of saturation of intensities of fluorescence light combined with ambient light at the second frequency relative to an intensity of ambient light at a third frequency.

8. The method according to claim 7, wherein the filtering through a beamsplitter comprises filtering through a dichroic beamsplitter.

9. The method according to claim 7, wherein the filtering through a beamsplitter comprises filtering through a dichroic mirror and one or more light filters.